DD Cooling was selected as the refrigeration engineering contractor for the project and was also commissioned to build the insulated cold store structures. DD Cooling brought in industrial CO₂ plant specialist Isentra to supply three independent dual temperature transcritical CO₂ systems and provide full system design and commissioning support.

Waitrose specified a highly resilient refrigeration requirement, so each CO₂ system was fitted with Isentra’s Full Resilience option, which includes back-up controls and standby pressure regulators for the systems, which have a combined heat rejection of circa 800 kW.

Isentra managing director Daniel Clark said: “Waitrose has been employing natural refrigerants to minimise its environmental impact for many years and the Greenford project extends the retailer’s existing CO₂ portfolio. The application of CO₂ refrigeration is rapidly becoming the leading cooling technology across a variety of applications in a wide number of sectors.

“CO₂ systems deliver exceptional cooling performance at low cost, while also being very attractive from a sustainability perspective, with an ultra-low global warming potential. CO₂ refrigeration is also a future proof refrigeration solution that will not be phased out, nor is it subject to costly management schemes or taxation.”

Dave Dobson from DD Cooling said: “Isentra has been a key partner on the project, supplying not only the CO₂ refrigeration plant, but providing comprehensive system design, coordination and commissioning.

“We believe the futureproof CO₂ systems installed at Greenford will deliver a highly resilient low energy refrigeration solution, and so we’re very pleased Waitrose is investing in this planet-friendly technology for such a major and high-profile installation.”